A Contra-rotating Variable Cycle Turbofan Engine

In a variable core flow engine, the corrected mass flow can be adjusted according to the flight conditions. The thermal efficiency can then be improved by decoupling the unfavorable relation between pressure ratio and corrected mass flow that exists in conventional turbofan engines. An innovative variable core flow engine using a statorless turbine and a variable inlet guide vane (VIGV) is investigated. The performance of the important components is studied and the working principle of the engine system is analyzed. The effects of this configuration on engine fuel consumption and weight are studied. The use of a contrarotating variable cycle turbofan is discussed in the light of the conclusions drawn from the statorless configuration.